# Computer Project BUS ADM 210, Fall 2015

Computer Project
DUE: MONDAY, DECEMBER 7 BY 11:59 P.M. TO THE D2L DROPBOX
Instructions:
1. Follow the directions for each problem.
2. Use JMP for all calculations. Answer the questions thoroughly by showing your JMP outputs. If your JMP
outputs are not submitted then you will not receive full credit on the problem.
3. You will upload ONE file to the D2L Dropbox. It will consist of a Word/PDF/other file format document
containing all of your work and JMP outputs. This is the only file that should be uploaded to D2L. While your
JMP file used in Problems 1 & 2 does not need to be uploaded, your instructor/TA reserves the right to ask you
for this file to verify your work.
4. In your Word/PDF/document organize your responses by clearly numbering the problems and sub-parts in order.
5. It is okay to work with other students. However, each student’s project submission must be a product of his or
her own solutions to the problems. Any projects that are the same will NOT BE GRADED.
6. Please do not hesitate to contact your instructor or TA if you have any questions about the project. Questions
should be asked in a timely manner, not at the last minute!
7. This project is out of 50 possible points, with 2 bonus points built into Problem 4.
There are 3 data sets you will use with regard to this project:
1. On Problems 1 and 2, you will create your own data set of 45 gas station prices (regular, unleaded gasoline).
2. On Problems 3 and 4, please use the data file HousesProject.jmp, which consists of a random sample of 24
houses for sale in the area around UWM. Variables are: list price of the home (the column called “Price”), the
number of bedrooms (the column called “Beds”), and square feet (the column called “SquareFeet”).
3. On Problem 5, please use the data file Titanic.jmp. In this data file is a two-way table that compares economic
status to whether or not the passengers survived the sinking of the Titanic.

Problem 1: (11 points) We are going to explore the price of regular, unleaded gasoline in the Milwaukee area.
a)

What is the population of interest?

b) Find the gas prices of regular, unleaded gasoline at 45 gas stations in the Milwaukee area. You can do this using the
suggested websites below or you can drive around and record prices. Note that these websites typically report results in
terms of cheapest gas prices first. Please take this into consideration when generating your sample of 45 gas stations, which
should theoretically be a random sample.
AAA: http://aaa.opisnet.com/index.aspx (Click on the “Automotive” tab along the top. Then along the left hand side click on
“Fuel Prices”. On the next screen click on “Launch Finder” under the heading “Fuel Price Finder”)

milwaukeegasprices.com or gasbuddy.com
In your Word/PDF/document please indicate the source of your gasoline prices (website used, did you drive around, how
did you randomly select 45, etc.).
There is no need to upload your JMP file to D2L. However, your instructor/TA reserves the right to request you to provide
this file, so please keep it saved.
c)

In JMP, construct a histogram of the regular unleaded prices of gasoline. Describe the distribution by giving its shape,
center, and spread according to the histogram.

d) Have JMP produce the following summary statistics:
i.
Mean
ii.
Standard deviation
iii.
Median
iv.
The first quartile, Q 1
v.

The third quartile,

Q3

Problem 2: (17 points). We are interested in estimating the mean price of unleaded gasoline in the Milwaukee area. Please answer
the following questions:
a)

Using the data from Problem 1, have JMP determine the 99% confidence interval for the mean gasoline prices. Report your
answer as an interval of prices rounded to two decimal places.

b) Give an interpretation of this confidence interval.
c)

AAA lists out that the average price of gasoline in the Milwaukee area last month was \$2.51. According to your data, can we
say there is a significant difference in the mean gasoline prices compared to last month?
i.
State the null and alternative hypotheses.
ii.

Describe the assumptions of this hypothesis test to determine if the test statistic you are using is appropriate. Fully
explain. Below are the four items you should comment on:
Does the Normality (or non-Normality) of your data set matter? Why or why not?
Is the population standard deviation, σ , known or unknown?
If σ is known, state what it is. If σ is unknown, state what we are using to estimate it.
Which distribution should we use to model probabilities related to the hypotheses?

iii.

Determine the p-value using JMP. Below are two suggested ways of doing this:
JMP’s Test Mean function
JMP’s Distribution Calculator: This can be found via Help Sample Data Teaching Scripts Interactive
Teaching Modules Distribution Calculator

iv.

Make a decision and state your conclusion to the hypothesis test in context of the original problem. Use a
significance level of α =0.01 (i.e. 1% significance level).

v.

Compare the results of your significance test to the 99% confidence interval for the mean gasoline price per gallon.
Does the conclusion in part (iv.) still hold for the confidence interval? Fully explain.

Part (c) of Problem 2 is used to test your Quantitative Literacy and will be graded on the following rubric:
Assessment Rubric (points)
Learning Outcome
Assessment Item
3
2
Students will
State the null and
Skillfully converts relevant
Completes conversion
recognize and
alternative
information into an appropriate
relevant information
construct
hypotheses to
and desired hypothesis,
into a hypothesis but
mathematical
determine if there are including using proper notation.
is only partially
models and/or
significant differences
appropriate or
hypotheses that
in the mean price of
accurate or uses
represent
gasoline.
improper notation.
quantitative
information.
Students will
evaluate the validity
of these models and
hypothesis.

1
Completes conversion
relevant information
into a hypothesis but is
inappropriate or
inaccurate.

Describe the
assumptions of this
hypothesis test to
determine if the test
statistic you are using
is appropriate.
Determine the pvalue of this
significance test using
JMP.

Accurately explains all 4 of the 4
bullet points listed above.

Accurately explains 3
of the 4 bullet points
listed above.

Accurately explains 1
or 2 of the 4 bullet
points listed above.

Analyses are attempted and all
problem. Analysis of the JMP
output is clearly and concisely
communicated.

Analyses are
attempted but are
the problem.

Students will reach
logical conclusions,
predictions, or
inferences.

Make a decision and
to the hypothesis test
in context of the
original problem.

Rejection or failure to reject the
null hypothesis is correctly
communicated, including reason
for decision.
Provides correct conclusion in
proper context.

Students will assess
the reasonableness
of their conclusions.

Compare the results
test to the 99%
confidence interval
for the mean gasoline
price per gallon.
Does the conclusion
in part (iv.) still hold
for the confidence
interval?

Uses the quantitative
information effectively as a basis
for deep and thoughtful
judgments in context. The
numerical results of the
confidence interval are explicitly
connected to the result of the
significance test. The
connection between the 99%
confidence interval and our
hypotheses at the 1%
significance level is properly

Analyses are
attempted but are
only partially correct
problem or analysis of
the JMP output is not
given.
Rejection or failure to
reject the null
hypothesis is correctly
communicated,
including reason for
decision.
Conclusion is not in
proper context or is
incorrectly stated.
Uses the quantitative
information correctly
but deeper
connections between
the confidence
interval and the
significance test are

Students will analyze
and manipulate
mathematical
models using
quantitative
information.

At attempt at a
decision and
both draw incorrect
conclusions on what
the information
means.
Uses the quantitative
information incorrectly
or does not provide
contextual basis for
the conclusion.
Connections between
the confidence interval
and the significance

Problem 3: (13 points) Using the JMP data set HousesProject.jmp, we want to determine if there is a significant difference in the
mean price of a 3-bedroom home compared to the mean price of a 4-bedroom home.
a) Give the summary statistics for the price of a 3-bedroom home versus a 4-bedroom home. The easiest way to generate this
is to go to Analyze Distribution and use “Price” in “Y, Columns” and Use “Beds” in the “By” window.
b) Create a side-by-side boxplot comparison between the price of 3-bedroom versus 4-bedroom homes. The easiest way to
generate this is to use Graph Builder. Go to Graph Graph Builder and drag “Price” into the Y area and “Beds” into the X
area. Then click on the boxplot icon along the top. Comment on the spread of the distributions and also on the medians of
the distributions.
c)

Is the mean house price for a 3-bedroom home significantly less than the mean house price for a 4-bedroom home?
i.
State the null and alternative hypotheses.
ii.
Use JMP to produce an output to test the difference in the means. Identify the appropriate p-value on the output.
iii.
Make a decision on the test at a significance level of α=0.02 .
iv.
State your conclusion to the question above in context.

d) Give the 95% confidence interval from the JMP output you used in part (c).
Problem 4: (4 points) Using the JMP data set HousesProject.jmp, we want to determine if the size of the house (SquareFeet) can
predict the list price (Price) of the home.
a)

Produce a scatterplot of Price (y axis) versus SquareFeet (x axis). Describe the form, direction, and strength of the
relationship between Price and SquareFeet. Note any potential outliers.

b) Using JMP, estimate the correlation coefficient between Price and SquareFeet.
c)

(Optional – worth 0.5 bonus points) Determine the simple linear regression line to predict Price using SquareFeet. In the
JMP output is the relationship significant at the 5% level? Justify your answer.

d) (Optional – worth 0.5 bonus points) What is the slope
respect to SquareFeet.

b1 ? Give the interpretation of what it means about the Price with

e) (Optional – worth 0.5 bonus points) Using the regression equation, predict the price of a 2000-square-foot home.
f)

(Optional – worth 0.5 bonus points) What percent of the variation in Price can be explained by this regression equation?

Problem 5: (5 points) In 1912 the British luxury passenger ship Titanic struck an iceberg and sank on its way to New York City. Think
of the Titanic disaster as an experiment in how the people of that time behaved when faced with death in a situation where only
some can escape, and consider the passengers from the data file Titanic.jmp as a sample from the population of their peers. We
want to determine if economic status and survival are independent.

Economic Status
Highest
Middle
Lowest
a)

Survival Status
Die
Survive
d
d
117
187
526
186
163
112

State the null and alternative hypotheses.

b) Produce a contingency table output in JMP. In this table, have JMP display the “Count,” “Expected,” and “Cell Chi Square”
values.
c)

Give the p-value and the decision from the test at the 5% significance level.

d) What do you conclude from this significance test at the 5% level? State your conclusion in the context of the problem.